Heart disease is the number one cause of death in the world. Cardiac events often occur in daily life and account for some 30% of mortalities in the U.S. Unfortunately, current medical technologies and procedures typically fail to prevent life-threatening acute cardiac events (e.g., heart attacks). This is because current technologies and procedures typically do not detect the risk precursors that can lead to such an event.
Two broad categories of tests are used in clinical practice to detect cardiac disorders, namely, “static” and “dynamic” tests. Static tests are essentially frozen snapshots of cardiac information, such as x-rays, computer images, and blood enzyme test results. This sort of testing is expensive and not always readily available. Dynamic tests are those that continuously monitor heart dynamics, such as when recording electrocardiograms (ECGs). There is an increasing appreciation for the benefits of continuously monitoring the dynamic details of cardiac functioning. If such monitoring were performed on an ongoing basis, for example, several times a day, each day, cardiac disorders could be detected earlier and acute cardiac events could be avoided. However, real-time ECG monitoring generates enormous amounts of data that are simply too large for humans to visually analyze.
Another limitation of current dynamic testing is that it generates relatively low-resolution information as to cardiac activity. Recent developments in electrocardiogram imaging (ECGI) promise to provide higher resolution sensing of cardiac electrical dynamics. Moreover, ECGI has been shown to substantially enhance the detection of certain cardiac disorders in their early stages. If ECGI could be continually performed and the collected data continually analyzed, physicians would have an unprecedented opportunity to observe high-risk subjects for cardiac disorders.
Recently, sensor-embedded “smart shirts” have been developed to monitor cardiac activity. Some smart shirts that include ECG electrodes have been proposed to collect a limited number of channels of ECG signals (i.e., <12 leads). Further, an ECGI system has been proposed to include hundreds of small electrodes, but not in the form of smart shirt. Although the electrodes can be successfully used to collect ECGI data, each electrode must maintain strict contact with the skin surface, typically requiring the use of sticky gels, connectors, and/or hard plastic chest straps. As a result, such shirts are uncomfortable to wear and therefore create patient compliance issues. Furthermore, the compact representation and interpretation of large spatiotemporal data from ECGI, which is essential for a functional cyber-physical infrastructure, has not been developed.
The above-described issues pose critical scientific and technological barriers for improving the outcomes of cardiac care services. It can therefore be appreciated that it would be desirable to have a wearable ECGI system and method that could be used to monitor patients and detect cardiac disorders that pose a significant health risk to patients.